There are many instances today, both in ordinary home use as well as in commercial or industrial environments, where there is a need to have a means of applying liquids, creams, ointments, lotions, gels, oils, paste, and the like, to a surface. Where such applications may be made in generous quantities across a large surface area, there is little need for a delivery system that provides careful control of the product being dispensed. Conversely, where the product needs to be dispensed with care due to the delicacy of the receiving surface, or where product needs to be applied only in specific locations while excluding adjacent surfaces, or where the high cost of product dictates the minimization of waste, the means and method of application acquire increasing importance.
Examples of the instances where such diligence is required in the application of a product are diverse, and may include the following: application of off-the-shelf skin creams or moisturizing lotions; ointments for treatment of dermatological conditions, burn treatment medicines, anti-bacterial treatment for cuts; scalp treatments; hair coloring; painting; applications of wood stain; dispensing glue; applying of shoe polish; decorating a cake; or applying mascara or other make-up.
Common methods of applying a liquid-like product unusually involve either use of a sponge or a brush that is used in combination with a storage container. One example is shown by U.S. Pat. No. 6,010,268 to Sereg. The Sereg patent describes a handle component that “is first filled with the liquid composition and then inverted and squeezed to force the liquid into the sponge component,” and that “as the sponge surface is wiped over the surface and the liquid retained therein becomes depleted, the handle is periodically squeezed to dispense more of the liquid as it is needed.” But the sponge of the Sereg patent does not lend itself very well to either careful control of the amounts of fluid dispensed to the sponge, above that which is achievable by a hand squeeze, or lend itself to the diligent application of product only to specific areas.
Another example is shown by U.S. Pat. No. 7,309,185 to Thorpe, which discloses a pen-type applicator, where a handle may be twisted so that a mechanical means causes a piston to translate and force material contained in a storage space to extrude out of an opening. The opening may provide material flow onto either a smooth applicator surface or one containing bristles that form a toothbrush. Although the Thorpe device offers a means of relative control over the quantity of product being delivered, it nonetheless provides a very course means of delivering the product to specific areas. As seen in FIG. 8, the device requires extrusion of product quantities sufficient to overhang the immediate bristles, but then relics on the generous quantity and subsequent contact with the receiving surface to achieve distribution to bristles on the periphery. The device is not tailored to independently direct the product with any precision to a specified surface, which may not be necessary for brushing ones teeth, but may be necessary for many other applications. The Thorpe device is also not adapted to accommodate the flow of materials having lower viscosities.
The applicator of U.S. Pat. No. 5,156,479 to Iizuka exhibits qualities more conducive to precise delivery of a specified quantity of product. The Iizuka device similarly has an opening through which the product is delivered, but the opening is at the end of an axial tube which forms the core of a cosmetic applicator brush. The applicator brush of Iizuka is not described in any detail, but similarly appears in each of the Figures as a pointed brush resembling an artist's script-type brush. The arrangement would permit pinpoint application of product, and the seemingly dense aggregation of bristles surrounding the axial tube could accommodate lower viscosity products better than the Thorpe device. However, the Iizuka applicator is limited to such pinpoint applications or linework, and would be very inefficient for covering larger surface areas.
The invention shown by U.S. Pat. No. 6,227,737 to Kageyama discloses a similar arrangement. Kageyama has a twist-type handle that translates a piston for delivery of product from an opening, but has for its delivery means a flat-tipped brush, which would be an improvement for delivery to areas other than those resembling simple linework. However, increasing the size of the brush merely provides for a proportional increase in potential coverage for a given stroke, but does not afford the fidelity that may be achieved with the script-type brush of Iizuka. Moreover, the pen arrangements of both Iizuka and Kageyama particularly lend themselves to application of product by a user while grasping and manipulating the device as if it were a writing implement.
The invention disclosed herein solves all of these problems found in the prior art using a valve system in a special applicator head, which creates a dual reservoir system, with its functionality being particularly well adapted for use in cosmetics as a mascara applicator.